Finite element simulation of road tanks for ADR and fatigue assessments

Abstract

Purpose – The paper aims to illustrate the application of a state-of-the-art fatigue prediction concept (IIW recommendations) to the ADR calculation requirements, in order to include failure-critical weld details to the strength assessment of road tanks. The level of calculation accuracy and, therefore, safety of such structures transporting dangerous goods can be substantially increased. Design/methodology/approach – A case study of a 2-compartment aluminum alloy LBGF tank used for the transportation of gasoline/petroleum products is conducted adopting the meshing directives of the structural hot spot stress concept (SHSSC) of the IIW recommendations for the weld details of the structure. The stresses on the prescribed Hot Spots are extracted from the solutions of each load case described in the ADR legislation and assessed both in terms of static strength according to EN 14286 and fatigue strength using the standardized IIW assessment curves (FAT curves). Findings – The detailed analysis of the road tank has successfully allocated the failure critical points of the structure. Additionally it has illustrated the ability of the embedded fatigue concept to accurately calculate the stresses which can later be used for the durability evaluation, providing that at least some operational load spectra become available. Research limitations/implications – The use of a global meshing and calculation concept offers a relatively limited accuracy level considering any individual weld detail. On the other hand, it offers a sufficient overview of the whole structure with minimum effort and costs. Practical implications – Time-consuming integrity inspections of road tanks can be minimized, as the failure critical locations are identified and therefore easily monitored. Furthermore, the transformation of the fatigue life prediction issued by the proposed calculation into actual operational time may be used to determine realistic time intervals between service pauses required for the safe operation of such structures. Originality/value – The present study constitutes the first approach of embedding the SHSSC into the calculation of large-scale structures such as road tanks and verifies the applicability of this concept beyond simple geometries and load cases.